Fluoroalkanesulfonate salts find diverse applications in areas such as photoacid generators, battery electrolytes, antistatic agents, flame retardants, and as precursors for fluorinated sulfonic acids and ionic liquids. For many of these applications, it is essential that the fluoroalkanesulfonate salts be highly pure and free of both organic and inorganic contaminants.
U.S. Patent Application 2006/0276671 discloses a process for the preparation of hydrofluoroalkanesulfonic acid by reaction of a fluoroolefin with an aqueous sulfite solution having a pH 4 to 12, and isolating the acid by distillation. In this disclosure acetone was employed as an extraction solvent. Fluoroalkanesulfonate salts prepared by these procedures may contain significant amounts of solvent or salt contaminants which are carried over from the synthetic process. There is a need for practical processes that provide highly pure fluoroalkanesulfonate salts.